London and Londoners in the Eighteen-Fifties and Sixties – Alfred Rosling Bennett, 1924:

The Westminster Company owned only some six or eight boats, which made non-stop runs between Old Swan Pier and an exclusive landing-stage that then existed at the southern end of Westminster Bridge on part of the site of the new County Hall. The Company’s business was chiefly to afford City men a prompt means of getting to and from Waterloo Station, their route anticipating in that respect the present City and Waterloo Tube; and immense crowds availed themselves of the facility. Morning and evening the boats were crowded and never deserted at any hour, not even on Sunday. […]. Their oriflamme was a black funnel with one white band, and their bell-mouthed tops were likewise of open work. They were all named after flowers: London Pride, Lotus, Azalea, Camellia, Sunflower, Dahlia, etc., the name being painted on the paddle-box.